In the poultry processing industry, usually there is a requirement that after preliminary processing, the eviscerated poultry carcass must be chilled prior to secondary processing or packaging for storage and shipment. A variety of mechanisms have been developed to achieve this chilling step, each with its own advantages and operational challenges. One such method is generically referred to as a rocker chiller. In such a chiller, a dasher oscillates within a semi-cylindrical tank to keep the carcasses stirred up in the heat exchanging liquid within the tank. Warm carcasses are added to the tank at one end and give up heat to the liquid in the tank as they migrate down the length of the tank. Cooler carcasses are removed at the opposite end of the tank.
It is desired that carcasses processed in a rocker chiller progress at a steady rate along the length of the chiller. The press of fresh product being added at the inlet pushes carcasses in the chiller toward the outlet end where space is created by removal of product from the tank. In this way, all carcasses should spend the same amount of time in the chiller and exit at similar temperatures. Ideally, the dasher moves carcasses from side to side in the tank, but does not displace them in the axial direction in a manner that would advance one carcass ahead of another in the sequence of progression through the tank. However, in some cases, the motion of the dasher creates surges that move carcasses back and forth along the axial dimension of the tank. In this situation, some carcasses inevitably advance faster than others resulting in a range of residence times and consequently a range of carcass temperatures at the exit. It is an intent of the current invention is to constrain the movement of carcasses through the chiller in a way that minimizes the variance of time the carcasses spend in the chiller.